865-49-6Relevant articles and documents
Brower,Hughes
, p. 7591,7592, 7595 (1978)
Kluger
, p. 2045 (1964)
Earing,Cloke
, p. 769 (1951)
A straightforward catalytic approach to obtain deuterated chloroform at room temperature
Higuera-Padilla, Angel Ruben,Kock, Flávio Vinícius Crizóstomo,Batista, Alzir Azevedo,Colnago, Luiz Alberto
, p. 917 - 920 (2020)
We report the catalytic activity for the complexes—cis-[RuCl2(dppb)(bipy)] (A), and [η6-(p-cymene)Ru (dppb)Cl]PF6 (B), wherein dppb = 1,4-bis(diphenylphosphine)butane, and bipy = 2,2′-bipyridine—for the synthesis of CDCl3 from CHCl3 using D2O as deuterium source. H/D exchange reactions were performed using a chloroform/D2O, 1:2 molar ratio, vigorously stirred, at room temperature. One mole of KOH was dissolved in D2O fraction and catalytic complexes from 0.002 to 0.05 mmol were dissolved in chloroform. The H/D exchange reactions were monitored using 13C nuclear magnetic resonance sequences without proton decoupling. The reaction using 0.01 mmol of compound A reached approximately 55percent of H/D conversion in 1 h. In the same time, the reactions with 0.002 mmol of compound A and without catalyst show approximately 28percent and 3percent H/D exchange, respectively. Without the catalysts, the H/D exchange was only 12.0percent in 5 h. For compound B, 55percent H/D conversion was observed in 1 h, only when 0.05 mmol was used, which is much higher catalyst concentration. After the isolation of the chloroform fraction and two more addition of D2O, it was possible to obtain 95.0percent H/D exchange in approximately 3 h, using 0.01 mmol of the compound A. Therefore, compound A is an efficient catalyst for a rapid and straightforward synthesis of CDCl3 from CHCl3 at room temperature and using D2O as deuterium source.
Novel chiral derivatizing reagent for the determination of enantiomeric excesses
-
, (2008/06/13)
A method for the determination of the enantiomeric composition of a chiral compound comprising (a) derivatising said chiral compound with a enantiomerically and diastereomerically pure compound of general formula I and (b) analysing the resulting mixture by an analytic technique. wherein Ar is an optionally substituted aromatic or heteroaromatic group.
Mechanisms and Products of Surface-Mediated Reductive Dehalogenation of Carbon Tetrachloride by Fe(II) on Goethite
Elsner, Martin,Haderlein, Stefan B.,Kellerhals, Thomas,Luzi, Samuel,Zwank, Luc,Angst, Werner,Schwarzenbach, Rene P.
, p. 2058 - 2066 (2008/12/21)
Aliphatic chlorinated hydrocarbons, including CCl4, are widespread groundwater contaminants. Mechanisms and product formation of CCl4 reduction by Fe(II) sorbed to goethite, which may lead to completely dehalogenated products or to form chloroform, a toxic product that is fairly persistent under anoxic conditions, were studied. A simultaneous transfer of two electrons and cleavage of two C-Cl bonds of CCl4 would completely circumvent chloroform production. Product formation pathways did not primarily depend on the competition between an initial one- and two-electron transfer, but on the presence of different radical scavengers and the properties of the mineral surface with respect to stabilization of reaction intermediates. Specific adsorption of major anions or pH effects could modify the capability of the goethite surface to stabilize short-lived radical intermediates.